Heating system



Jan. 12 1926.

- L. M. ELLIS HEATING SYSTBII Filed July 8, 1922 gnu:-

Patented Jan. 12, 1926.

UNITED STATES 1,568,961 E T F C LEWIS ELLIS, or coNNnRsvILLE, INDIANA, AssIeNon T wINsLow SAFETY HIGH PRESSURE BOILER COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

HEATING SYSTEM.

Application filed Jul 8,1922. Serial No. 573,603.

To all whom it may concern:

' Be it known that I, LEWIS M. ELLIS, a

citizen of the United States, residing at Connersville, in the county of Fayette and State of Indiana, have invented a certain new and useful Improvement in Heating Systems, of whichthe following is a full, clear,concise, and exact description, reference being had to the accompanying drawings forming a part of this specification.

The present invention relates to heating systems, and pertains generally to that class of heatingapparatus having application to ovens, kilns, vats and the like, designed for" drying and processing.

One of the principal objects of the invention is to provide a heating system employing steam at low or nominal pressures, but

perature and circulated in a comparatively large volume. Another object ride an improved method. of and means for heating which will be capable of employing air and steam in alternate order or in conjunction with each other. According to one conception of my invention I propose using air exclusively in the initial warming up of the system. This preheats the conduits, the radiating surfaces, im peller and all other surfaces with which the heating medium contacts so that when the steam is finally introduced into the system, the entire, system will be at such a temperature that there will'be a minimum tendency for condensation. j

According to the preferred embodiment, the steam is circulated through a system characterized by the use of large sheet metal pipes and conduits and by the use of hol-, low metal walls, floors and ceilings surrounding the kilns or ovens. The system may be thus likened to a furnace pipe system employing a large volume of steam circulated at a comparativelylowpressure. The steam is preferably introduced into the system from an outside source and may be comparatively wet or saturated, this wet steam being first superheated inthesuperheating unit before being circulated through the'closed system. The initial preheating or the system by thecirculation of heated air therethrough minimizes the superheated to a comparatively high tem of my invention is topro do occur after the circulation of the super heated body of steam has been built up may be replenished by the admission of more steam from the outside source.

The accompanying drawing is a diagrammatic representation of a preferred.

embodiment of my improved heating system. The body of air or steam is circulated through the system under the impelling" action of a suitable centrifugal blower 1. The tangential outlet 2 of the blower discharges into the manifold conduit 3 which flares out to make connection with the plu rality of transverse heating tubes 4. in" the heater 5., This heater may be of any pre-' ferred type and construction, being pref 'erably of a type, however, having direct convection of heat from the combustion chamber to the heating tubes. Inthe con ventional form of heater shown, the tubes 4t extend between insulated side walls 6" across one or more heating flues extending long tudinally ofthe setting. A combus tion chamber 7- isprovided in the lower part of the setting, and a perforated fire arch 8 is preferably. extended across the combustion chamber. As above mentioned,

the products of combustion from the cham- 7 her 7 are preferably brought into contact" withthe air tubes 4 by" circulating the products of combustion around the tubes through one .or more passes above the arch8.

'The air from the blower l may be giver'i'v a single pass through the tubes 4, or, if de sired, the tubes can be connected in series so as to compel the air to gothrough a series of passes transversely of, the heater; The heated air is discharged into a manifoldll which covers the ends .of the tubes'discharg ing from the side" wallof the heater, this manifold communicating 'with a conduit or a system ofconduits 12 extending to the various ovens, kilns or the like to beheatd. An oven or kiln is diagrammatically inns-y trated at 14 being illustrative ,jof any enclo sure adaptedto be heated; This enclosure is surrounded on oneor more sides by outer walls 15 which define heating chambers or; jackets 161 These heating chamber-s16 are representative of hollowuvalls, partitions, floors and ceilings, such as-are now used on a large scale in systems employing heated losses from condensatiombut such losses as air' under comparatively low pressure} v The heating chambers of the oven or series of ovens are connected to a common return conduit 18 which extends back to the central intake 19-01? the blower l. The volume of steam. which is introduced in the system after the preliminary warming up by the circulation of heated air is preferably introduced into this return conduit 18. This insures that the live steam entering the system will be forced to circulate through the heater 5 before contacting with any of the heating walls of the ovens or the connecting conduit system. The steam is introduced through any suitable pipe 21, preterably in the form of a nozzle having its outlet directed in the course of flow to add the impulse of the steam to the circulation. This steam nozzle is supplied from any suitable boiler 22 under the control of a valve 23, the steam delivered therefrom being of any desired pressure and temperature. (,lenerally this steam will be drawn from any convenient source of supply and will hence be wet or saturated. The blower 1. is driven in any suitable manner, as through the belt 2& engaging over the pulley The speed of the blower 1 may be made rcgulatable so as to control the velocity of the circulation and thereby the quantity of heat conveyed to the oven or enclosure 11. A suitable flap valve 26 is pivoted at 2? to cover a discharge outlet in the return conduit 18, through which discharge outlet the air can be expelled when changing from air to steam.

\Vhen the system is put into operation, combustion is initiated in the heater 5 and the blower l is put into motion for impelling a circulation of air through the tubes and through the system for the preliminary warming of the system. After the system has been brought up to the desired temperature, as for minimizing condensation, the

,valve 23 is opened and steam is gradually introduced into the system through the nozzle 21. The tlap valve Q6 in the return conduit 18 is opened and the heated air is discharged through the valve opening as it is displaced by the volume of steam entering through the nozzle 21. Steam is admitted into the system until the most efiicient pressure is obtained consistent with the character of the system. The present system is characterized by the use of sheet metal conduits of large volume, and large volume heating chambers in the walls, floors and ceilings of the oven or kiln, and consequently the pressure of the steam must be maintained comparatively low to prevent leakage or rupturing of these conduits or heating chambers. By virtue of the above characteristics the present system is capable of effectively utilizing air as the heating medium, so that for emergency use, and possibly for certain classes of heating, air may be utilized in lieu of steam. The use of steam in the present system has inherent thermal advantages, however, over the use of air, particularly in the higher specific heat of the steam, which is much in excess of that of air, and the higher heat conductivity of the steam. Any steam losses from the system are replenished by the introduc' tion of further steam through the nozzle 21. When coolii'ig off or stopping the operation of the system, it may be desirable to shut ott' the steam a few minutes in advance and admit air in its place so as to prevent the accumulation of moisture in the conduits and heating chambers when the temperature drops below that of the steam, which moisture might be precipitated from the condensation of steam if the operation were interrupted with steam in the conduits.

The type ot heater illustrated at 5 admirably" servcs the two-told function o'l heating the relatively large volume ol air circulated through the system, and also of superheating the relatively large volume ot steam when that is circulated through the system. The st am at nominal or low pressures is superheated in this heater to a temperature above saturation for circulation through the system. The rate of heat transfor can be regulated through a considerable range by controlling the rate of tiring at the heater 5 and the speed of the blower 1.

l claim:

1.. In a steam heating system, a blower for circulating a volume of air through the system, said blower including an inlet and outlet, a heater having a plurality of heating passages through which the air circulated by the blower is adapted to be passed. a conduit connecting the outlet of the said blower to the plurality of passages in the said heater, a heating chamber, a conduit for conducting the air to the said heating chamber, a return conduit for conducting the air from said heating chamber to the inlet of said blower, a nozzle for introducing steam into the system after the same has been preheated by the heated air, and a valve in the said return conduit for venting the air from said system after the latter has been preheated.

2. The method of heating in a system of the class described, which consists in circulating a volume of air through the system, heating the air for preheating the system, circulating a volume of steam through the system after it has been preheated by the volume of air, and venting the air displaced from the system by the. steam.

3. The method of heating in a system of the class described. which consists in circulating a volume of air through the system, heating the air for preheating the system and for causing the air to absorb moisture therein, circulating a volume of steam through the system after it has been preheated by the volume of air to displace the air from the system, and venting the air displaced from the system by the steam.

4. The method of heating in a system of the class described which consists of circulating a volume of steam through the system, circulating a volume of air through the system to absorb moisture therein, and displacing the air by a second volume of steam.

5. The method of heating in a system of the class described Which consists of circulating a volume ofsteam through the system, circulating a volume of air through the system, heating the air to cause it to preheat the system and to absorb condensate therein, displacing the volume of air by a second volume of steam, and venting the displaced air from the said system.

6. In a steam heating system, means for circulating a volume of air through the system, means for heating the circulated air, a heating-chamber adapted to be preheated by the circulated air, means for introducing steam into the system after the system has been preheated by the circulated air, and means for discharging the air from the system after the system has been preheated.

7 In a steam heating system, means for circulating a volume of air through the system, means for heating the air for preheating the system and for causing the air to absorb moisture therein, means for circulating a volume of steam through the system after it has been preheated by the air, said volume of steam displacing the volume of air therein, and means for allowing the air displaced to escape from the system. I

In Witness whereof, I hereunto subscribe my name this 28th day of June, 1922.

LEWIS M. ELLIS. 

